Crossbow safety system

ABSTRACT

Provided is a crossbow safety system comprising a crossbow, optic fence, and interlock. The crossbow may have a bowstring operable between a cocked and an uncocked position, the cocked position and the uncocked position defining between them a bowstring plane, and a trigger assembly adapted to selectably retain the bowstring in the cocked position. The optic fence may be adapted to detect an obstruction in a safety plane coincident with the bowstring plane or offset below the bowstring plane by some offset distance. The optic fence may have an infrared emitter adapted to output IR radiation, and a photodiode adapted to sense the output IR radiation from the infrared emitter. The interlock may be operationally engaged with the optic fence and the trigger assembly. The interlock may be adapted to lock the trigger assembly from releasing the bowstring if the optic fence detects an obstruction in the safety plane.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/478,306, filed Mar. 29, 2017, the entirety of which is fullyincorporated by reference herein.

I. BACKGROUND

The present subject matter is directed to crossbows. More specificallythe present subject matter is directed to an interlock system for acrossbow to prevent unsafe operation.

There are multiple technical challenges present in current crossbowtechnology. Some of these challenges relate to user safety andsatisfaction. Unlike some other conventional weapons, a crossbow maypresent an opportunity for a user to grip the weapon in a way thatpositions a body part, such as the user's finger or other portion of theuser's hand, in the path of the bowstring of the crossbow as it movesfrom the cocked to the uncocked positions during firing. Suchpositioning of a body part in the path of the bowstring may lead toundesirable performance and potential user injury.

It remains desirable to provide an interlock system for a crossbow thathelps to prevent unsafe or otherwise undesirable operation.

II. SUMMARY

In accordance with one aspect of the present subject matter provided isa crossbow safety system comprising a crossbow, optic fence, andinterlock. The crossbow may have a bowstring operable between a cockedand an uncocked position, the cocked position and the uncocked positiondefining between them a bowstring plane, and a trigger assembly adaptedto selectably retain the bowstring in the cocked position. The opticfence may be adapted to detect an obstruction in a safety planecoincident with the bowstring plane or offset below the bowstring planeby some offset distance. The optic fence may have an infrared emitteradapted to output IR radiation, and a photodiode adapted to sense theoutput IR radiation from the infrared emitter. The interlock may beoperationally engaged with the optic fence and the trigger assembly. Theinterlock may be adapted to lock the trigger assembly from releasing thebowstring if the optic fence detects an obstruction in the safety plane.

Still other benefits and advantages of the present subject matter willbecome apparent to those skilled in the art to which it pertains upon areading and understanding of the following detailed specification.

III. BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take physical form in certain parts and arrangement ofparts, embodiments of which will be described in detail in thisspecification and illustrated in the accompanying drawings which form apart hereof and wherein:

FIG. 1 is a perspective view of one embodiment of a crossbow safetysystem.

FIG. 2 is a schematic diagram of the components in one embodiment of acrossbow safety system.

FIG. 3 is a perspective view of one embodiment of a crossbow safetysystem.

FIG. 4 is a perspective view of one embodiment of a crossbow safetysystem.

FIG. 5 is a perspective view of one embodiment of a crossbow safetysystem.

IV. DETAILED DESCRIPTION

Referring now to the drawings wherein the showings are for purposes ofillustrating embodiments of the present subject matter only and not forpurposes of limiting the same, and wherein like reference numerals areunderstood to refer to like components, provided is a crossbow safetysystem and a method for using same.

In a first embodiment, a crossbow safety system 100 may comprise acrossbow 120, an optic fence 160, and an interlock 180.

The crossbow 120 may comprise a bowstring 122, and a trigger assembly130. The bowstring 122 may be operable between a cocked position 123 andan uncocked position 124. The cocked position 123 and the uncockedposition 124 define between them a bowstring plane 125. The bowstringplane 125 is the region through which the bowstring passes as ittransitions from the cocked position 123 to the uncocked position 124.The bowstring sweeps through the bowstring plane 125 as it transitionsfrom the cocked position 123 to the uncocked position 124. In onenon-limiting embodiment, the bowstring 122 extends between a set ofcrossbow limbs 138, 139 and may be moved between the cocked position 123and the uncocked position 124 by moving a section of the bowstring 122along the beam 140. The trigger assembly 130 may be adapted toselectably retain the bowstring 122 in the cocked position 123. Thecrossbow is discharged, and any associated arrow operatively engagedwith the bowstring 122 is fired, by triggering the crossbow 120. Thistriggering may also be called a firing operation. Triggering thecrossbow 120 causes the trigger assembly 130 to release the bowstring122 from the cocked position 123. The crossbow 120 may have a foregrip126. A foregrip is adapted to be grasped by an associated hand of anassociated user during operation. One common use of the foregrip 126 isto support the crossbow during a firing operation.

The optic fence 160 is a photosensitive array operating in a safetyplane 162 either coincident with the bowstring plane 125 or offset belowthe bowstring plane 125 by some offset distance. A plane in which theoptic fence 160 operates may be referred to as a safety plane 162. Theoptic fence 160 is adapted to detect an obstruction in a safety plane162. Without limitation, there may be more than one safety plane 162 insome non-limiting embodiments. It is not critical that the safety plane162 be parallel with the bowstring plane 125: it may be parallel withthe bowstring plane 125 in some non-limiting embodiments and may benon-parallel with the bowstring plane 125 in some other non-limitingembodiments. In certain embodiments, the safety plane 162 is positionedbetween a space that is safe for a the hand of a user or fingers of auser or other body parts of a user, and the space containing thebowstring plane 125 so that if the user accidentally has his hand orfinger or other body part in the space containing the bowstring plane125 during an attempted firing operation, the user will also obstructthe safety plane 162 such that the interlock functionality as describedbelow results.

The optic fence 160 may have an emitter 164 adapted to outputelectromagnetic radiation, and a photodiode 166 adapted to sense theradiation output from the emitter 164. In some non-limiting embodiments,the emitter 164 may be adapted to output: infrared (IR) radiation of oneor more wavelengths in the range from 2000 nm to 700 nm; light of one ormore wavelengths in the range from less than 700 nm to 400 nm; orultraviolet radiation of one or more wavelengths in the range from lessthan 400 nm to 300 nm. In some non-limiting embodiments, the emitter 164may be an LED or other type of IR source chosen with good engineeringjudgment. In some non-limiting embodiments, the emitter 164 may be a 940nm wavelength LED adapted to output IR radiation. In some non-limitingembodiments, the photodiode 166 may be sensitive to: infrared (IR)radiation of one or more wavelengths in the range from 2000 nm to 700nm; light of one or more wavelengths in the range from less than 700 nmto 400 nm; or ultraviolet radiation of one or more wavelengths in therange from less than 400 nm to 300 nm. In some non-limiting embodimentsthe photodiode 166 is sensitive to all or part of the wavelength rangefrom 350 nm to 1100 nm. In some non-limiting embodiments the photodiode166 has a peak sensitivity in the wavelength range from 960 nm to 1000nm. In some non-limiting embodiments the optic fence 160 may comprise areflector 168 adapted to reflect the electromagnetic radiation output bythe emitter 164 from the reflector 168 and to the photodiode 166. Insome non-limiting embodiments the reflector 168 may be adapted toreflect output IR radiation from the infrared emitter 164 to thephotodiode 166. An obstruction of the safety plane may block theelectromagnetic radiation output by the emitter 164 and prevent it frombeing properly received by the photodiode 166. If the electromagneticradiation output by the emitter 164 is properly received by thephotodiode 166 then the optic fence 160 will detect a clear safety plane162 and may output a signal indicating that the safety plane 162 is notobstructed or may fail to output a signal indicating that the safetyplane 162 is obstructed. If the electromagnetic radiation output by theemitter 164 is not properly received by the photodiode 166 then theoptic fence 160 will not detect a clear safety plane 162 may output asignal indicating that the safety plane 162 is obstructed or may fail tooutput a signal indicating that the safety plane 162 is unobstructed. Acomputer, such as computer 190 or a computer in an operatively engagedassociated device, may be used to compare the electromagnetic radiationoutput by the emitter 164 and the electromagnetic radiation received bythe photodiode 166 to determine if the electromagnetic radiation outputby the emitter 164 is properly received by the photodiode 166.

The optic fence 160 may comprise one or more of a power source, powercord 172, a power switch 173, a battery indicator light 174, an externalwarning indicator light 175, a scope display 176. A power source for anoptic fence may comprise a battery or any source of electrical powerchosen with good engineering judgment. The power source provideselectrical power sufficient to run the emitter 164, the photodiode 166,and any other components of the optic fence 160. The power cord 172 is awire or cable or other electrical conductor that is operatively engagedto conduct electrical power between the power source and othercomponents of the optic fence 160. The power switch 173 may allow anassociated user to selectably turn the power source on or off. A batteryindicator light 174 may provide output to a user indicating thecondition of a battery such as battery charge remaining. An externalwarning indicator light 175 may be used to indicate to an associateduser obstruction of the safety plane 162. A scope display 176 may beused to indicate to an associated user obstruction of the safety plane162. A scope display 176 may show an indication as a projection withinthe view through a scope 177.

In some non-limiting embodiments, the optic fence 160 may beoperationally engaged with a computer 190. In some non-limitingembodiments, the computer 190 may be a cellular phone, or tablet, orother device. The operational engagement between the optic fence 160 andthe computer 190 may be by any Bluetooth, infrared, radio signal, or anyother wired or wireless communication device 193 or method adapted tooperationally interface the optic fence 160 and the computer 190 chosenwith good engineering judgment. In some non-limiting embodiments, thesystem 100 comprises a communication device 193 adapted to operationallyinterface with an associated cellular phone 195 to transmit data to, andreceive data from, the associated cellular phone 195. In somenon-limiting embodiments, the system 100 comprises a communicationdevice 193 adapted to operationally interface with an associatedcellular phone 195 which may act as a computer usable by the system 100;in such embodiments the associated cellular phone 195 may perform one ormore of the computer functions that could otherwise be performed bycomputer 190, or the associated cellular phone 195, which by its naturecomprises a type of computer itself, may replace or be the computer 190.In some embodiments the computer 190 or associated cellular phone 195may have access to information about the system 100, from GPS or othersensors chosen with good engineering judgment, including, but notlimited to, conditions such as cocked or uncocked status, loaded orunloaded status, user identification, time, location, orientation, lightconditions, an event log, obstruction of the safety plane, lack ofobstruction of the safety plane, or combinations thereof. Where thesystem is capable of gathering information about location andorientation, the system may permit triangulation or other calculationsto be performed in order to provide estimate of ranges or otherdistances.

In some non-limiting embodiments the system 100 may comprise pulsesignal generator 196 or a pulse signal reader 198, or both. In somenon-limiting embodiments the optic fence 160 or components thereof, suchas emitter 164 or photodiode 166, may be part of or may be operationallyengaged with a pulse signal generator 196 or a pulse signal reader 198,or both. In some non-limiting embodiments, the emitter 164 may part of apulse signal generator 196 adapted to send information, such as, andwithout limitation, information about the system 100 as described above,encoded as IR pulses or other electromagnetic pulses. In somenon-limiting embodiments, the photodiode 166 may part of a pulse signalreader 198 adapted to receive information encoded as IR pulses or otherelectromagnetic pulses. A computer 190 or associated cell phone 195 mayprovide a signal to a pulse signal generator 196 comprising emitter 164which causes it to emit a pulsed electromagnetic signal encodinginformation. A pulse signal reader 198 comprising a photodiode 166 mayreceive a pulsed electromagnetic signal encoding information and provideto a computer 190 or associated cell phone 195 a signal representativeof the pulsed electromagnetic signal encoding information. The computer190 or associated cell phone 195 may in turn decode the encodedinformation in the signal representative of the pulsed electromagneticsignal encoding information. Without limitation in embodiments in whichthe photodiode 166 is sensitive to IR, the photodiode 166 may be part ofa pulse signal reader 198 adapted to receive information encoded as IRpulses. Without limitation in embodiments in which the emitter 164 is anIR emitter 164, the infrared emitter 164 may be part of a pulse signalgenerator adapted to send information encoded as IR pulses. A system 100equipped with a pulse signal generator 196 and a pulse signal reader maycommunicate information about the system 100 with other similarlyequipped systems.

The interlock 180 is operationally engaged with the optic fence 160 andthe trigger assembly 130. In some embodiments, the interlock 180 isadapted to lock the trigger assembly 130 from releasing the bowstring122 if the optic fence 160 does not detect a clear safety plane 162. Insome embodiments, the interlock 180 is adapted to lock the triggerassembly 130 from releasing the bowstring 122 if the optic fence 160detect an obstruction of the safety plane 162. In certain embodiments,the interlock 180 will lock the trigger assembly 130 from releasing thebowstring 122 unless it receives a release signal 186 from the computer190 to release the interlock 180 and the computer 190 will only providethe release signal 186 to the interlock 180 if the optic fence 160detects a clear safety plane 162. In certain embodiments, the interlock180 will lock the trigger assembly 130 from releasing the bowstring 122unless it receives a release signal 186 from the computer 190 to releasethe interlock 180 and the computer 190 will only provide the releasesignal 186 to the interlock 180 if the optic fence 160 does not detectan obstructed safety plane.

In operation, a crossbow safety system 100 may be operated by providinga crossbow safety system 100 as described above; using the optic fenceto detect for an obstruction in the safety plane by emitting IRradiation from the infrared emitter and using the photodiode to sensefor any IR radiation; comparing the electromagnetic radiation output bythe emitter 164 and the electromagnetic radiation received by thephotodiode 166 to determine if the electromagnetic radiation output bythe emitter 164 is properly received by the photodiode 166, where thislatter comparison operation may comprise comparing the IR radiationemitted from the infrared emitter to any IR radiation sensed by thephotodiode; and operating the interlock wherein operation of theinterlock locks the trigger assembly from releasing the bowstring if theoptic fence does not detect a clear safety plane, or operation of theinterlock unlocks the trigger assembly to permit release of thebowstring if the optic fence detects a clear safety plane.

Operation of the crossbow safety system may further compriseoperationally engaging the optic fence with a computer and using thecomputer to compare the IR radiation emitted from the infrared emitterto any IR radiation sensed by the photodiode.

Operation of the crossbow safety system may further compriseoperationally interfacing the system with an associated cellular phone;transmitting data to the associated cellular phone; and receiving datafrom the associated cellular phone.

Operation of the crossbow safety system may further comprise providing areflector adapted to reflect output IR radiation from the infraredemitter to the photodiode; and reflecting output IR radiation from theinfrared emitter to the photodiode with the reflector.

Non-limiting embodiments have been described, hereinabove. It will beapparent to those skilled in the art that the above methods andapparatuses may incorporate changes and modifications without departingfrom the general scope of the present subject matter. It is intended toinclude all such modifications and alterations in so far as they comewithin the scope of the appended claims or the equivalents thereof.

Having thus described the invention, it is now claimed:
 1. A crossbow safety system comprising: a crossbow having a bowstring operable between a cocked and an uncocked position, the cocked position and the uncocked position defining between them a bowstring plane, and a trigger assembly adapted to selectably retain the bowstring in the cocked position; an optic fence adapted to detect an obstruction in a safety plane coincident with the bowstring plane or offset below the bowstring plane by some offset distance, the optic fence having an infrared emitter adapted to output IR radiation, a photodiode adapted to sense the output IR radiation from the infrared emitter; and an interlock operationally engaged with the optic fence and the trigger assembly, and adapted to lock the trigger assembly from releasing the bowstring if the optic fence does not detect a clear safety plane
 162. 2. The crossbow safety system of claim 1, wherein the infrared emitter is an LED.
 3. The crossbow safety system of claim 2, wherein the infrared emitter is a 940 nm wavelength LED.
 4. The crossbow safety system of claim 3, wherein the photodiode is sensitive to all or part of the wavelength range from 350 nm to 1100 nm.
 5. The crossbow safety system of claim 4, wherein the photodiode has a peak sensitivity in the wavelength range from 960 nm to 1000 nm.
 6. The crossbow safety system of claim 1, wherein the optic fence is operationally engaged with a computer.
 7. The crossbow safety system of claim 6, wherein the system comprises a communication device adapted to operationally interface with an associated cellular phone to transmit data to, and receive data from, the associated cellular phone.
 8. The crossbow safety system of claim 7, wherein the infrared emitter is part of a pulse signal generator adapted to send information encoded as IR pulses.
 9. The crossbow safety system of claim 8, wherein the photodiode is part of a pulse signal reader adapted to receive information encoded as IR pulses.
 10. The crossbow safety system of claim 9, wherein the optic fence further comprises a reflector adapted to reflect output IR radiation from the infrared emitter to the photodiode.
 11. A method of operating a crossbow safety system comprising: providing a crossbow safety system having a crossbow having a bowstring operable between a cocked and an uncocked position, the cocked position and the uncocked position defining between them a bowstring plane, and a trigger assembly adapted to selectably retain the bowstring in the cocked position, an optic fence adapted to detect for an obstruction in a safety plane coincident with the bowstring plane or offset below the bowstring plane by some offset distance, the optic fence having an infrared emitter adapted to output IR radiation, a photodiode adapted to sense for the output IR radiation from the infrared emitter, and an interlock operationally engaged with the optic fence and the trigger assembly, and adapted to lock the trigger assembly from releasing the bowstring if the optic fence detects an obstruction in the safety plane; using the optic fence to detect for an obstruction in the safety plane by emitting IR radiation from the infrared emitter and using the photodiode to sense for any IR radiation; comparing the IR radiation emitted from the infrared emitter to any IR radiation sensed by the photodiode; operating the interlock wherein operation of the interlock locks the trigger assembly from releasing the bowstring if the optic fence to does not detect a clear safety plane, or operation of the interlock unlocks the trigger assembly to permit release of the bowstring if the optic fence detects a clear safety plane.
 12. The method of operating a crossbow safety system of claim 11, further comprising: operationally engaging the optic fence with a computer; and using the computer to compare the IR radiation emitted from the infrared emitter to any IR radiation sensed by the photodiode.
 13. The method of operating a crossbow safety system of claim 12, wherein the infrared emitter is an LED.
 14. The method of operating a crossbow safety system of claim 13, wherein the infrared emitter emits infrared radiation at a wavelength of 940 nm.
 15. The method of operating a crossbow safety system of claim 14, wherein the photodiode is sensitive to all or part of the wavelength range from 350 nm to 1100 nm.
 16. The method of operating a crossbow safety system of claim 15, wherein the photodiode has a peak sensitivity in the wavelength range from 960 nm to 1000 nm.
 17. The method of operating a crossbow safety system of claim 12, further comprising operationally interfacing the system with an associated cellular phone; transmitting data to the associated cellular phone; and receiving data from the associated cellular phone.
 18. The method of operating a crossbow safety system of claim 17, wherein the infrared emitter is part of a pulse signal generator adapted to send information encoded as IR pulses; and wherein the photodiode is part of a pulse signal reader adapted to receive information encoded as IR pulses.
 19. The method of operating a crossbow safety system of claim 18, further comprising providing a reflector adapted to reflect output IR radiation from the infrared emitter to the photodiode; and reflecting output IR radiation from the infrared emitter to the photodiode with the reflector.
 20. A crossbow safety system comprising: a crossbow having a bowstring operable between a cocked and an uncocked position, the cocked position and the uncocked position defining between them a bowstring plane, and a trigger assembly adapted to selectably retain the bowstring in the cocked position; an optic fence adapted to detect an obstruction in a safety plane offset below the bowstring plane, the optic fence having an 940 nm wavelength LED infrared emitter adapted to output IR radiation, the 940 nm wavelength LED infrared emitter being part of a pulse signal generator adapted to send information encoded as IR pulses, a photodiode adapted to sense the output IR radiation from the infrared emitter, the photo diode being sensitive to all or part of the wavelength range from 350 nm to 1100 nm, having a peak sensitivity in the wavelength range from 960 nm to 1000 nm, and part of a pulse signal reader adapted to receive information encoded as IR pulses, and a reflector adapted to reflect output IR radiation from the infrared emitter to the photodiode; a communication device adapted to operationally interface with an associated cellular phone to transmit data to, and receive data from, the associated cellular phone, the associated cellular phone comprising a computer; and an interlock operationally engaged with the optic fence and the trigger assembly, and adapted to lock the trigger assembly from releasing the bowstring if the optic fence does not detect a clear safety plane. 